Coffee shops in Maastricht only accept dutch citizen. If you are working in the netherlands or here for study, you can register at the GBA register. (when you rent a room or appartment). With the GBA inscription and your passport or ID card is the only way for a tourist to enter a Maastricht coffeeshop. The closest town or cities where they do accept foreigners are Kerkrade, Eindhoven or Tilburg.